130 Insect Pests. 



way of getting rid.iof them. Some use sulphur, some gunpowder, 

 and then dig them out ; perhaps these are the best ways. Experience 

 has shown that cyanide of potassium is no better than the old 

 country methods. 



One point only may perhaps be worth drawing attention to, and 

 that is, that we must keep a look-out for the so-called arboreal 

 builders. The Vcsjm sykcsfris and V. norwegica form their beautiful 

 hanging nests in trees, shrubs, even in kale-pots; these must be 

 sought for and destroyed wiih the ground-wasp nests. The best plan 

 seems to be to mark them in daytime and burn them down with a 

 paraffin torch at night. 



Wasps do much harm in vineries ; there they may be kept out 

 by seeing all openings and opened windows are covered with wasp 

 netting. This may be improved on in vineries by using muslin, so as 

 to exclude the grape fly at the same time. 



It is certainly advantageous, by offering small rewards, to have 

 all the queen wasps destroyed early in the year. 



THE APPLE APHIDES. 



{Aphis pomi, De Geer, Aphis sorhi, Kaltenbach, Aphis fitchii, 

 Sanderson.) 



At least three true aphides are abundant on the apple in Great 

 Britain, damaging the foliage, also deforming the shoots and spoiling 

 the fruit.* A bad attack took place during 1904 in Britain of these 

 Apple Aphides. Scarcely a fruit-growing district was free from these 

 pests, and in many orchards the leaves were so hopelessly curled that 

 washing was of no avail whatever. Feeding not only on the leaves 

 and blossoms, but on the young shoots, they distort them to a serious 

 extent, as shown in the photograph (Fig. 104). In one instance on 

 two trees kept under observation, it was found that the aphis lessened 

 the .growth of certain shoots by 70 per cent., and a few shoots died 

 right back (Fig. 103). 



The great importance of these insects led me to investigate their 

 life-history, which has not been done dc novo in this country. The 

 result (1) has been so far satisfactory in that it has shown when 

 these fruit pests are most vulnerable to attack and when we can 

 follow that excellent adage : " Prevention is better than cure." What 



* The Apple Aphides have been wrongly treated by Ormerod, Whitehead, 

 etc., as a single species, Aphis mali, Fabricius. 



